121,940 research outputs found
Aspects of three-dimensional MHD : magnetic reconnection and rotating coronae
No full textSolutions of the magnetohydrodynamic (MHD) equations are very important for modelling laboratory, space and astrophysical plasmas, for example the solar and stellar coronae, as well as for modelling many of the dynamic processes that occur in these different plasma environments such as the fundamental process of magnetic reconnection. Our previous understanding of the behavior of plasmas and their associated dynamic processes has been developed through two-dimensional (2D) models. However, a more realistic model should be three-dimensional (3D), but finding 3D solutions of the MHD equations is, in general, a formidable task. Only very few analytical solutions are known and even calculating solutions with numerical methods is usually far from easy.
In this thesis, 3D solutions which model magnetic reconnection and rigidly rotating magnetized coronae are presented. For magnetic reconnection, a 3D stationary MHD model is used. However, the complexity of the problem meant that so far no generic analytic solutions for reconnection in 3D exist and most work consists of numerical simulations. This has so far hampered progress in our understanding of magnetic reconnection. The model used here allows for analytic solutions at least up to a certain order of approximation and therefore gives some better insight in the significant differences between 2D and 3D reconnection. Three-dimensional numerical solutions are also obtained for this model.
Rigidly rotating magnetized coronae, on the other hand, are modeled using a set of magnetohydrostatic (MHS) equations. A general theoretical framework for calculating 3D MHS solutions outside massive rigidly rotating central bodies is presented. Under certain assumptions, the MHS equations are reduced to a single linear partial differential equation referred to as the fundamental equation of the theory. As a first step, an illustrative case of a massive rigidly rotating magnetized cylinder is considered, which somehow allows for analytic solutions in a certain domain of validity. In general, the fundamental equation of the theory can only be solved numerically and hence numerical example solutions are presented. The theory is then extended to include a more realistic case of massive rigidly rotating spherical bodies. The resulting fundamental equation of the theory in this case is too complicated to allow for analytic solutions and hence only numerical solutions are obtained using similar numerical methods to the ones used in the cylindrical case
Three-dimensional solutions of the magnetohydrostatic equations : rigidly rotating magnetized coronae in spherical geometry
No full textContext. Magnetohydrostatic (MHS) equilibria are often used to model astrophysical plasmas, for example, planetary magnetospheres or coronae of magnetized stars. However, finding realistic three-dimensional solutions to the MHS equations is difficult, with only a few known analytical solutions and even finding numerical solution is far from easy. Aims. We extend the results of a previous paper on three-dimensional solutions of the MHS equations around rigidly rotating massive cylinders to the much more realistic case of rigidly rotating massive spheres. An obvious application is to model the closed field line regions of the coronae of rapidly rotating stars. Methods. We used a number of simplifying assumptions to reduce the MHS equations to a single elliptic partial differential equation for a pseudo-potential U, from which all physical quantities, such as the magnetic field, the plasma pressure, and the density, can be derived by differentiation. The most important assumptions made are stationarity in the co-rotating frame of reference, a particular form for the current density, and neglect of outflows. Results. In this paper we demonstrate that standard methods can be used to find numerical solutions to the fundamental equation of the theory. We present three simple different cases of magnetic field boundary conditions on the surface of the central sphere, corresponding to an aligned dipole field, a non-aligned dipole field, and a displaced dipole field. Our results show that it should be possible in the future to use this method without dramatically increasing the demands on computational resources to improve upon potential field models of rotating magnetospheres and coronae.Peer reviewe
The economics of tobacco in Lebanon: An estimation of the social costs of tobacco consumption
No full textObjectives: Assess the socioeconomic costs of smoking in Lebanon and understand the tobacco market and identify the winners and losers from the Lebanese tobacco trade. Methods: We take a close look at the market for tobacco and related markets to identify the main stakeholders and estimate the direct costs and benefits of tobacco. We also estimate lower bounds for the costs of tobacco, in terms of lost productivity, the cost of medical treatment, lost production due to premature death, and environmental damage. The paucity of data means our cost estimates are conservative lower bounds and we explicitly list the effects that we are unable to include. Results: We identify the main actors in the tobacco trade: the Régie (the state-owned monopoly which regulates the tobacco trade), tobacco farmers, international tobacco companies, local distributors, retailers, consumers, and advertising firms. We identify as proximate actors the Ministries of Finance and Health, employers, and patients of smoking-related illnesses. In 2008, tobacco trade in Lebanon led to a total social cost of $326.7 million (1.1percent of GDP). Conclusion: Low price tags on imported cigarettes not only increase smoking prevalence, but they also result in a net economic loss. Lebanese policymakers should consider the overall deficit from tobacco trade and implement the guidelines presented in the Framework Convention on Tobacco Control to at once increase government revenue and reduce government outlays, and save the labor market and the environment substantial costs. © 2014 Informa Healthcare USA, Inc.Ammar W., 2009, HLTH POLITICS; [Anonymous], 2007, STAT B; Byblos Bank, 2010, LEB THIS WEEK; Chaaban J, 2010, EC TOBACCO LEBANON E; Chaaban J., 2008, ARE STAKEHOLDERS RAS; Chaaya M, 2004, ADDICT BEHAV, V29, P1821, DOI 10.1016-j.addbeh.2004.04.008; Collins D. J., 2010, SOCIAL COSTS SMOKING; Easton B., 1997, PUBLIC HLTH MONOGRAP, V2; Eriksen M., 2012, TOBACCO ATLAS; Global Burden of Diseases Injuries and Risk Factors Study, 2010, GBD PROF LEB; Investment Development Authority of Lebanon (IDAL), 1996, RESTR REG; Lebanese Customs, 2007, TRAD STAT; Lebanese Fire Prevention Committee (LFPC), 2010, EFF FOR FIR; Ministry of Finance, 2010, PUBL FIN REV 2008; Saade G, 2005, PREV MED, V47, pS15; Salti N., 2013, TOBACCO CONTROL; Sibai A. M., 2009, COMMUNICATION; Tiihonen J., BMJ OPEN, V2, DOI [10.1136-bmjopen-2012-001678, DOI 10.1136-BMJ0PEN-2012-001678]; World Bank, 2006, LEB PROD INV CLIM PR; World Bank, 2008, WORLD DEV IND; World Bank, 2010, DEC INC SUPP TOB PRO; World Health Organization, 2013, ENF BANS TOB ADV PRO0
Relative deprivation and mortality in South Africa
No full textThis paper tests the relative income hypothesis by considering the relationship between mortality, income and relative deprivation in South Africa using individual-level data on income and five measures of relative deprivation each with a different reference group. We find that income tends to be protective of, and relative deprivation detrimental to health, but the latter often gives a better account of mortality than does income alone. For some population groups the fit is improved in specifications which include both income and relative deprivation. Overall, there seems to be solid evidence in support of the relative income hypothesis, particularly for the more economically disadvantaged population groups. Relative deprivation is especially significant when age is the reference group, suggesting that the comparison of socio-economic standing that has an impact on health tends to happen within cohorts. The results are robust to splitting the sample into urban-rural subsamples and to looking at the incidence of illness as the health outcome rather than mortality. While little is known about the mechanisms underlying the effect of relative deprivation on health and mortality, the consistent evidence in favor of age as a reference group, particularly in a context like South Africa's suggests that intra-cohort comparisons should be an avenue for more in depth investigation. © 2009 Elsevier Ltd. All rights reserved.Alesina A, 1999, Q J ECON, V114, P1243, DOI 10.1162-003355399556269; ANDERSON LR, 2004, 14 COLL WILL MAR DEP; Brunner E., 1999, SOCIAL DETERMINANTS; Chen Z, 2008, SOC SCI MED, V66, P2206, DOI 10.1016-j.socscimed.2008.01.016; Craig N, 2005, SOC SCI MED, V60, P2477, DOI 10.1016-j.socscimed.2004.11.018; Deaton A., 2001, 8099 NBER PRINC U RE; Eibner Christine, 2004, J Ment Health Policy Econ, V7, P167; Eibner C, 2005, J HUM RESOUR, V40, P591; Ellison GTH, 2002, SOC SCI MED, V54, P561, DOI 10.1016-S0277-9536(01)00052-1; Gerdtham UG, 2004, J HUM RESOUR, V39, P228, DOI 10.2307-3559011; GRAVELLE H, 2008, J HLTH EC, V27, P1462; Hou F, 2005, SOC SCI MED, V60, P1557, DOI 10.1016-j.socscimed.2004.08.033; Jones AM, 2008, J HEALTH ECON, V27, P308, DOI 10.1016-j.jhealeco.2007.05.007; Jones K., 2004, GEOGRAPHY HLTH INEQU; Kawachi I., 2006, HLTH NATIONS WHY INE; Kawachi I, 1997, AM J PUBLIC HEALTH, V87, P1491, DOI 10.2105-AJPH.87.9.1491; Kawachi I, 2007, J NATL I PUBLIC HLTH, V56, P114; Kawachi I, 1999, SOC SCI MED, V48, P719, DOI 10.1016-S0277-9536(98)00400-6; Kondo N, 2009, J EPIDEMIOL COMMUN H, V63, P461, DOI 10.1136-jech.2008.078642; Kondo N, 2008, SOC SCI MED, V67, P982, DOI 10.1016-j.socscimed.2008.06.002; Larrea C, 2005, SOC SCI MED, V60, P165, DOI 10.1016-j.socscimed.2004.04.024; LINDLEY J, 2005, SHEFFIELD EC RES PAP; MARMOT MG, 1994, DAEDALUS, V123, P197; McLeod CB, 2003, AM J PUBLIC HEALTH, V93, P1287, DOI 10.2105-AJPH.93.8.1287; OSLER M, 2002, BRIT MED J, V324, P1; Runciman W. G., 1966, RELATIVE DEPRIVATION; SAPOLSKY RM, 1993, RECENT PROG HORM RES, V48, P437; Shibuya K, 2002, BRIT MED J, V324, P16, DOI 10.1136-bmj.324.7328.16; Subramanian SV, 2003, J EPIDEMIOL COMMUN H, V57, P844, DOI 10.1136-jech.57.11.844; Subramanian SV, 2004, EPIDEMIOL REV, V26, P78, DOI 10.1093-epirev-mxh003; Subramanian SV, 2007, J EPIDEMIOL COMMUN H, V61, P802, DOI 10.1136-jech.2006.053801; TRIEGAARDT J, 2008, S AFRICA OUR BIGGEST; Wagstaff A, 2000, ANNU REV PUBL HEALTH, V21, P543, DOI 10.1146-annurev.publhealth.21.1.543; Whiteford A, 2000, STUDIES EC ECONOMETR, V24, P7; Wilkinson R., 2001, INCOME SOCIOECONOMIC; YITZHAKI S, 1979, Q J ECON, V93, P321, DOI 10.2307-188319766
Catherine Salti, La Relation
No full textGauthier-Darley Michel. Catherine Salti, La Relation. In: Raison présente, n°122, 2e trimestre 1997. Avons-nous tord d'être universalistes ? pp. 151-152
Allocladius salti Ferrington Jr & Saether 2011, comb. n.
No full textAllocladius salti (Freeman) comb. n. (Fig. 19 G) Pseudosmittia salti Freeman, 1954: 442, pro parte. Smittia nigra, Freeman, 1956: 349, pro parte, not Kieffer 1913: 28, not Freeman, 1953: 206. Allocladius niger (Freeman); Freeman & Cranston 1980: 181, pro parte, not Kieffer 1913: 28. Material examined: TANZANIA: Kilimanjaro, Shira Plateau, sweeping bog grass at 12,100 feet, holotype male, 27.xi.1948, G. Salt (495)(BMNH). Diagnostic characters: The male imago can be separated from other species with more than 3 acrostichals, supraalar setae, large superior volsella and with large lobe-like accessory lobe of the inferior volsella by having R 4+5 ending far proximal of the end of M 3+4 and an AR of about 0.84. Male imago (n = 1) All measurements and ratios are within the variation of A. aizaiensis with the following exceptions: Total length/wing length 1.54; wing length/length of profemur 3.11; AR 0.84; terminal flagellomere 333 µm long; tentorium 151 µm long; stipes 139 µm long; 5 prealars; VR 1.41; no costal extension; R 4+5 ends far proximal of end of M 3+4; BV 3.70; BR 1 4.2; gonostylus 64 µm long; HR 2.89; and HV 3.63. Remarks Freeman (1954: 442) described a mixed collection of A. salti and A. niger. There is a female, which we have not examined with the same data as the holotype in the BMNH. However, since we do not have an associated female of A. niger we would not be able to assign that female to a species. Distribution The species is known with certainty only from the type locality in Tanzania.Published as part of Ferrington Jr, Leonard C. & Saether, Ole A., 2011, A revision of the genera Pseudosmittia Edwards, 1932, Allocladius Kieffer, 1913, and Hydrosmittia gen. n. (Diptera: Chironomidae, Orthocladiinae) 2849, pp. 1-314 in Zootaxa 2849 (1) on pages 75-77, DOI: 10.11646/zootaxa.2849.1.1, http://zenodo.org/record/528820
Efficacy and safety of insulin glargine and glimepiride in subjects with Type 2 diabetes before, during and after the period of fasting in Ramadan
No full textAims To determine the safety and efficacy of insulin glargine and glimepiride in patients with Type 2 diabetes before and after Ramadan and during fasting for Ramadan. Methods In this open, descriptive, multi-centre, prospective study, insulin-naïve (n = 100) or previously insulin-treated (n = 249) patients with Type 2 diabetes received insulin glargine [titrated from 10 U daily according to fasting blood glucose (FBG)] and glimepiride (4 mg daily). The number and type of hypoglycaemic episodes and glycaemic control were assessed before, during and after Ramadan. Bivariate logistic regression analyses were used to identify factors which predicted hypoglycaemia during Ramadan. Results Only one episode of severe hypoglycaemia occurred in each time period before, during and after Ramadan. Mild hypoglycaemic episodes increased from 156 pre-Ramadan to 346 during Ramadan (P 0.001) and decreased to 153 post-Ramadan (P = 0.0002).The increase during Ramadan was mainly attributed to increased symptomatic hypoglycaemic episodes. FBG and glycated haemoglobin improved during the titration period and did not change during the rest of the study. Risk of hypoglycaemic events during Ramadan was higher in countries where fasting is strict [odds ratio (OR) 3.69 (2.06-6.63), P 0.0001]. Lower weight [ 70.0 kg; OR 2.56 (1.46-4.48), P = 0.001] and waist circumference [ 90 cm; OR 3.06 (1.62-5.78), P = 0.001] increased the risk of hypoglycaemia during Ramadan whilst FBG 6.7 mmol-l [OR 0.3 (0.17-0.54), P 0.0001] had a protective effect. Conclusions Combination of insulin glargine and glimepiride may be used during Ramadan in patients with Type 2 diabetes who wish to fast, provided glimepiride is given at the time of breaking the fast and insulin glargine titrated to provide FBG 6.7 mmol-l. © 2009 Diabetes UK.Akram J, 1999, DIABETIC MED, V16, P861; Al-Arouj M, 2005, DIABETES CARE, V28, P2305, DOI 10.2337-diacare.28.9.2305; Mafauzy M, 1990, Med J Malaysia, V45, P14; Anwar A, 2006, Med J Malaysia, V61, P28; Bolli GB, 2002, INT J CLIN PRACT, P65; Cesur M, 2007, DIABETES RES CLIN PR, V75, P141, DOI 10.1016-j.diabres.2006.05.012; Chandalia HB, 1987, PRACTICAL DIABETES, V4, P287, DOI 10.1002-pdi.1960040610; Duckworth W, 2009, NEW ENGL J MED, V360, P129, DOI 10.1056-NEJMoa0808431; Gerstein HC, 2008, NEW ENGL J MED, V358, P2545; ISMAIL MMA, 2003, DIABETES RES CLIN PR, V50, P71; Kadiri A, 2001, DIABETES METAB, V27, P482; Kassem HS, 2005, J ENDOCRINOL INVEST, V28, P802; Kodiri A, 1998, PRACT DIABET S1, V15, pS5, DOI DOI 10.1002-PDI.1960150906; LAAJAM MA, 1990, E AFR MED J, V67, P732; Mafauzy M, 2002, DIABETES RES CLIN PR, V58, P45, DOI 10.1016-S0168-8227(02)00104-3; Mattoo V, 2003, DIABETES RES CLIN PR, V59, P137, DOI 10.1016-S0168-8227(02)00202-4; Mucha GT, 2004, DIABETES CARE, V27, P1209, DOI 10.2337-diacare.27.5.1209; Riddle MC, 2003, DIABETES CARE, V26, P3080, DOI 10.2337-diacare.26.11.3080; Salti I, 2004, DIABETES CARE, V27, P2306, DOI 10.2337-diacare.27.10.2306; Skyler JS, 2009, CIRCULATION, V119, P351, DOI 10.1161-CIRCULATIONAHA.108.191305; Uysal AR, 1998, DIABETES CARE, V21, P2033, DOI 10.2337-diacare.21.11.2033; Wild S, 2004, DIABETES CARE, V27, P1047, DOI 10.2337-diacare.27.5.104724
Natural-Resource Wealth: Elbow Grease or Fuel for Poverty?
No full textWe consider the effect of natural resources on growth using a two-sector model (resource and nonresource). Government taxes the nonresource sector and chooses institutional quality, which determines productivity in the nonresource sector and the government's ability to appropriate resource rents. We find that resource booms harm institutions. Their effect on growth depends on relative sector sizes: when rents are more substantial, governments are likelier to corrupt institutions to secure larger shares of rents. Cross-country panel data substantiate the results: countries in the bottom tercile of value added in manufacturing and services divided by GDP are cursed by resources; others are blessed. © 2011 Mohr Siebeck
La resistenza ai salti : pliometria e affaticamento pliometrico (parte seconda)
No full textIn molte discipline sportive il modello della prestazione richiede la ripetizione, spesso in successione rapida, di un elevato numero di salti o di rimbalzi realizzati in modalità ciclica o con differenti forme di impulso. Per descrivere la capacità di eseguire efficacemente queste azioni motorie si è proposto di utilizzare il termine resistenza ai salti, intendendo con esso la capacità di mantenere l’efficienza prestativa del gesto, realizzato in condizioni di regime pliometrico o di lavoro a carattere pliometrico, nonostante l’affaticamento. Nelle azioni di balzo eseguite con modalità intermittente, come nel caso della pallavolo o effettuate in forma ciclica, come in alcune discipline dell’atletica leggera, ci si chiede quali siano i meccanismi che intervengono a limitare la prestazione. Dopo avere illustrato, nella prima parte (cfr. n. 72) alcuni lavori di ricerca che si sono occupati di questo argomento, rivolti a sforzi di tipo molto prolungato, in questa seconda parte si illustrano alcune evidenze scientifiche basate su studi nei quali sono stati valutati gli effetti di serie di 100 salti e rimbalzi realizzati in particolari condizioni sperimentali, che sembrerebbero assegnare, nel processo di affaticamento conseguente ad una successione ripetuta di salti, maggiore importanza alle caratteristiche di tipo neuromuscolare piuttosto che alle cosiddette qualità aerobiche, e le conseguenze applicative che se ne ricavano
Nonmydriatic retinal image review at time of endocrinology visit results in short-term HbA1c reduction in poorly controlled patients with diabetic retinopathy.
No full textThe objective of this study was to evaluate the effect of discussing retinal findings following nonmydriatic retinal imaging during an endocrinology visit on subsequent HbA1c in poorly controlled diabetic patients with diabetic retinopathy (DR). During a visit to an endocrinologist, patients with DR and documented HbA1c ≥ 8.0percent within the preceding month were assigned to either addition of nonmydriatic imaging and discussion of retinal findings or standard endocrinology evaluation alone. Ophthalmology care was otherwise the same in both groups. Changes in HbA1c were evaluated 3 months later. One hundred thirteen (94percent) of the original 120 subjects completed the study. The mean HbA1c change in the retinal imaging group was a decline of 1.35percent, whereas the control group had a 0.26percent increase. Controlling for gender, age, duration of diabetes, presence of hypertension, and use of insulin, the difference between groups was significant (p0.0003). Nonmydriatic imaging and discussion of retinal findings during an endocrinologist visit may contribute, at least in the short term, to improved glycemic control in patients with DR and elevated HbA1c
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